So mostly fixable as soon as someone cares? The tools are tough (can’t make an opinion without details, and some people have idiosyncratic tool use and will never be satisfied by alternatives) but performance and ergonomics are presumably chugging along just fine; and will get a huge boost when Apple launches.

And yes, there will be the raw Linux kernel hackers who will not beh happy (but presumably such people are hardly happy using a Mac today...) Meanwhile for people who operate at a higher level, either in VMs/interpreted (PHP, JVM, Perl, Python, JS, ...) or generic C/C++ life is theoretically fine.

The big issue, then, is are they, eg, willing to change from perhaps using Dev Studio in Windows on Mac to using XCode? In the absence of data, I don’t think we can conclude anything (beyond that a lot of people will feel compelled to say “never, over my dead body” and then extrapolate aggressively, but with zero data, to the rest of the population).
Beyond which I could certainly imagine an MS-Apple deal that brings Dev Studio ARM to the ARM Mac (probably a win-win for both parties)...